17) Richard Frye, MD, PhD - Cerebral Folate Metabolism Abnormalities in Neurodevelopmental Disorders 

I also mention this because i've seen a lot of people's fingernails, and lots and lots of people barely have moons, yet we're supposed to have moons on all fingers (as well as toes) and they should be at least halfway up the nail, and not just behind or slightly above the cuticle. So that means, technically, lots of people are deficient in Folate, even though blood work may be fine (because Folic Acid gets into the blood stream, yet not much gets into the body in comparison), and it's likely causing people some issues, you would think. I mean they now process grains like wheat which reduces nutrition content including Folate, they have GMO crops now like Corn and Soy which use Glyphosate and other Shikimate inhibitors which apparently Shikimate is involved in crop Folate production (as well as Tyrosine and Tryptophan and other things) and so the GMO crops have no Folate (or Tryptophan for that matter), and then on top of that they add Folic Acid to the food supply and supplements which sucks compared to actual Folate, and plus people rarely eat liver or high Folate veggies and such these days and if they do eat veggies they mostly cook them or freeze them or can them and that breaks down/wastes Folate content, so i'm willing to bet a lot of people are low in Folate. Which imo doesn't mean Folic Acid doesn't work, it obviously works to some degree for some birth defects, but something tells me only a little bit of Folate is really required for that anyways, but Folate is also involved in many other things and especially in the body likely requires a sufficient supply (just as with any other vitamin or mineral or medicine) to be maximally/optimally effective, and so while we may be reducing some birth defects, we're still lacking in Folate which is causing a lot of issues, most likely. Just something to think about.

And remember, Folate works together with the other B vitamins, as well as some minerals and such, so relying solely on Folate probably isn't going to be as effective as say Folate+B12, Riboflavin, Niacin, B6 (P5P, not Pyridoxine), possibly Thiamine and B5 and i think even Biotin, and then like Zinc, Magnesium, Copper, and so on, all of which are involved in some way or another in metabolic and enzymatic processes whether used directly as co-factors or indirectly through other means/enzymes.

Find a functional Dr who could order a FRAT test for you.